The large-scale analysis of gene expression profiles was the first hallmark in the transition from structural genomics to functional genomics. Genomic-scale expression profiling experiments require large technical and computational investments to facilitate both experimentation and the analysis of the large data sets produced. These investments are beyond the capabilities of most laboratories or small groups. To provide access to these important technologies, the DMA Microarray Core, operating within the Vanderbilt Microarray Shared Resource (VMSR) has been established with major support from the VDDRC, the Diabetes Research and Training Center, the Vanderbilt-lngram Cancer Center (VICC), and the Vanderbilt University Medical Center Office of Research. The objectives of this core are to assist investigators in performing genomic investigations using high-throughput and cutting-edge technologies that are financially or technically prohibitive to utilize in individual labs. The services in the core have been substantially increased since the last application. While previous services were limited to cDNA-based arrays produced in the core for mouse and human, current services include a variety of commercial array platforms in addition to comprehensive oligonucleotide arrays for mouse and human. Supported commercial arrays include Affymetrix, Applied Biosystems, and CodeLink. In addition to gene expression profiling services, the core offers high-throughput genotyping services using the Affymetrix mapping arrays and Targeted Genotyping (ParAllele) platforms. Verification of microarray results (expression and genotyping) by real-time PCR is also available. The newest services established in the core are profiling of microRNAs and the manipulation of gene expression via RNAi and cDNA over-expression to support functional screens. The core continues to maintain a comprehensive informatics program with two full-time analysts available. Significantly, the core has developed an on-line project management system that supports all sample submission, project annotation, and data access through an efficient web interface. Since 2002, the core has published several manuscripts, processed hundreds of samples for VDDRC investigators, and continued to expand and refine services to meet the research needs of the Vanderbilt DDRC. The Core provides investigators with cutting edge access to human genomic technologies in order to prevent, diagnose or improve treatment of digestive diseases and disorders.